Collaborative Research: NSFGEO-NERC: P2C2--Understanding Trans-Hemispheric Modes of Climate Variability: A Novel Tree-Ring Data Transect spanning the Himalaya to the Southern Ocean

对支配跨半球气候联系以及热带和高纬度之间气候联系的机制还没有很好的了解。造成这种知识差距的原因是缺乏对过去气候变化的高分辨率和准确日期记录。数据覆盖面的稀疏性以及缺乏西太平洋地区共同的气候振荡模式限制了对年际至年代际时间尺度上更大尺度气候遥相关的理解。该项目旨在开发一个新的温度和水文气候变化数据网络，覆盖从喜马拉雅山到南大洋的500-1000年的样带。这是一个由国家科学基金会地球科学理事会（NSF/GEO）和联合王国国家环境研究理事会（NERC）通过NSF/GEO-NERC牵头机构协议共同资助的项目。该协议允许美国/英国提交一份联合提案，并由研究者拥有最大预算比例的机构进行同行评审。一旦成功地共同确定了一个奖项，每个机构资助的预算和与自己的国家相关的调查人员的比例。研究人员将重新利用现有的树木年轮样本收集从更广泛的季风亚洲下降到南中纬度地区，并使用一个新的示踪剂（代理），蓝光强度，作为温度和水文气候的指标。这一新的代用指标将加强以前几乎完全基于单一总环宽参数的气候分析，并将用于模拟和重建北方和南半球之间大气-海洋变化的关键模式。具体来说，研究人员将利用这些数据来解决以下问题：（1）过去热带和南半球火山事件的气候影响是什么？(2)热带辐合带和厄尔尼诺南方涛动在过去的500-1000年里是如何变化和相互作用的，正如在热带印度太平洋地区所表现的那样？（3）在过去的一千年里，南半球环状模是如何变化的，它是如何被热带和其他强迫所驱动的？潜在的更广泛影响包括更好地了解气候敏感但数据稀少的东半球过去的变化，其中包括地球仪上一些最易受气候影响的地区。这些数据将通过公共资料库和在科学会议上向更广泛的科学界传播，并将纳入今后的《亚洲季风干旱地图集》。该项目将支持莱德大学的三名本科生的培训，促进哥伦比亚大学和莱德大学之间的国家合作，以及与英国，捷克共和国，澳大利亚和新西兰大学的国际合作。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The mechanisms that govern trans-hemispheric climate linkages and those between the tropics and higher latitudes are not well understood. This gap in knowledge is caused by a lack of high resolution and well dates records of past climate variability. The sparsity of the data coverage as well as the lack of common climate oscillatory modes in the western Pacific region limits the understanding of broader-scale climate teleconnections on interannual to decadal time scales. This project aims to develop a new data network of temperature and hydroclimate variability across a transect spanning from the Himalaya to the Southern Ocean and extending back to 500-1000 years. This is a project that is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own country.The researchers will repurpose existing tree ring samples collected from the broader monsoon Asia down to the southern middle latitudes and use a new tracer (proxy), blue light intensity, as an indicator of temperature and hydroclimate. This new proxy will enhance prior climate analyses based almost entirely on the single total ring-width parameter and will be used to model and reconstruct key modes of atmosphere-ocean variability between the northern and southern hemispheres. Specifically, the researchers will use these data to address the following questions: (1) What are the climatic impacts of past volcanic events in the tropics and Southern Hemisphere? (2) How have the Intertropical Convergence Zone and El nino Southern Oscillation varied and interacted over the past 500-1000 years as expressed across the tropical Indo-Pacific region? and (3) How has the Southern Annular Mode varied over the past millennium, and how is it driven by tropical and other forcing?The potential broader impacts include an improved understanding of past variability in the climate-sensitive yet data-sparse Eastern Hemisphere which includes some of the most climatically vulnerable regions of the globe. These data will be disseminated to the broader scientific community via public repositories and at scientific conferences; and will be included in a future iteration of the Monsoon Asia Drought Atlas. The project will support the training of three undergraduate students at Rider university and foster national collaborations between Columbia University and Ryder University and international collaborations with universities in the UK, Czech republic, Australia and New Zealand.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.